Section 348. Payment of cost of state thruways

The state shall construct or
  improve  and maintain, at its own cost and expense, or with federal aid,
  state thruways, and shall acquire at its own cost and expense,  or  with
  federal  aid  or by gift, the rights of way necessary for such thruways.
  Such cost to the state shall, except for the preparation  of  plans  and
  specifications  and for engineering and other services incidental to the
  preparation of plans and  specifications  including  field  surveys  and
  sub-surface  investigations,  be  paid  only  from  moneys  specifically
  appropriated for such purpose, subject to the provisions of this chapter
  relating to federal aid; provided, however, that where any state highway
  or part thereof specified in section three  hundred  forty-one  of  this
  chapter  or  any improvement or reconstruction thereof shall be utilized
  by the commissioner of transportation as a part of  any  state  thruway,
  moneys  appropriated  for  the  construction and reconstruction of state
  highways may be expended therefor and rights of way  therefor  shall  be
  acquired as provided in article three of this chapter.